Sort out the exothermic and endothermic reactions among the following:
(i) `C (s) + 2H_2(g) to CH_4(g) , DeltaH = - 17.89 cal`
(ii) `CO(g) + 1/2O_2(g) to CO_2(g) = +284.5 kJ`
(iii) `2HCl (g) to 2H(g) + 2Cl(g), DeltaH = + 857 kJ`
(iv) `Cl_2(g) + 242kJ to 2Cl(g)`

Explanation

To determine whether the given reactions are exothermic or endothermic, we will analyze the sign of ΔH (change in enthalpy) for each reaction.

### Step-by-Step Solution:

1. **Identify the reactions and their ΔH values:**
- (i) \( C (s) + 2H_2(g) \rightarrow CH_4(g), \Delta H = -17.89 \, \text{cal} \)
- (ii) \( CO(g) + \frac{1}{2}O_2(g) \rightarrow CO_2(g), \Delta H = +284.5 \, \text{kJ} \)
- (iii) \( 2HCl(g) \rightarrow 2H(g) + 2Cl(g), \Delta H = +857 \, \text{kJ} \)
...